This invention relates generally to computer controlled systems and particularly to a switch arrangement for selectively accessing the computer of such a system in accordance with a desired sequence and assigned priorities.
Typically, in accessing a computer, the accessing commands are categorized into groups. The accessing commands within each group are presented differently to the computer dependent upon the manner in which the computer is intended to execute the commands. As an example, some commands can be categorized into an either-or type of group wherein the availability of one accessing command acts to the exclusion of all other commands within the group. This type of group, therefore, assures that only one command from the group is available to the computer at a given instance. Another category can be a priority type of group. Several commands of a priority group can be simultaneously presented to the computer and the computer executes the commands in an order established by priority assignments to the various commands. Another category can be a random type of group in which a plurality of commands can be simultaneously presented to the computer and the computer executes the commands at any time after all commands from higher priority groups are executed.
An example of a computerized system which uses the three categories of access command groupings set out above is a 3-in-1 lighthouse which is used to expose a photosensitive material during the application of a black matrix to the faceplate panels of color kinescopes. In this type of lighthouse, the faceplate panel and the lensing/lighting system of the lighthouse are moved relative to one another to three different positions. The black matrix material present on the inside surface of the kinescope panel is exposed to light at each of the three positions to form the matrix lines which separate the three colors of phosphor stripes which are subsequently placed on the panels. The computer utilized to control the relative movements of the panels and the lensing/lighting system, therefore, must respond to accessing commands which are categorized into the three categories set out above. The switches used to input the accessing commands are categorized identically to the commands. For example, switches which are categorized in the either-or group are the set-up and run switches. It is essential that only one of these switches access the computer at a particular time. Therefore, when either of these switches accesses the computer, the other switch is prevented from doing so. The switches which are used to provide manual commands for the relative movement of the panel and the lensing/lighting system fit into the priority type of grouping because, typically, these three switches are simultaneously closed. The switches are given priority assignments which result in movement to the three positions in the sequence which minimizes the amount of motion. Thus, the switch which results in travel from the home position to the nearest color position is given the highest priority.
Switches which fall into the random type of group are the switches used to return the lensing/lighting system to the home position, to reset the system or to calibrate the system. Any number of these switches can be actuated at a particular time and the computer executes the commands after all commands from the other groups are executed.
The instant invention is directed to a switch arrangement for accessing a computer in accordance with a variety of switch groupings.